An Open-label, Dose Escalation Trial to Evaluate the Safety and Pharmacokinetics of HMPL-523 in Patients With Lymphoma

This is a Phase I, open-label, multicenter study of HMPL-523 administered orally to patients
with relapsed or refractory lymphoma who have exhausted approved therapy options. This study
consists of a dose escalation stage (Stage 1) and a dose expansion stage (Stage 2).

Dose Escalation Stage (Stage 1) Dosing will begin at 100 mg once daily (QD). A cycle of study
treatment will be defined as 28 days of continuous dosing. The modified 3+3 design will be
applied for dose escalation and MTD determination to limit the number of patients exposed to
potentially ineffective or unsafe doses. The study will enroll 1 patient and the patient will
be treated for a 28-day cycle in the initial dose cohort. If there is no Dose Limiting
Toxicity (DLT) and no more than 2 treatment-emergent adverse events (TEAEs) of Common
Terminology Criteria for Adverse Events (CTCAE) Grade ≤2 in the first treatment cycle, the
study will be escalated to the next dose cohort and continue with the standard 3+3 design.
Otherwise, the trial will revert to a standard 3+3 design from the initial dose cohort. A
minimum of 3 patients will be enrolled and observed for toxicity in each successive dose
cohort after the initial dose cohort. If the 3 patients initially enrolled in a given dose
cohort complete the DLT assessment window (Cycle 1, Days 1-28) without experiencing a DLT, 3
patients will be enrolled at the next higher dose level. If 2 or more of the initial 3
patients enrolled at any dose level experience a DLT during the DLT assessment window, the
dose escalation will be halted. If 1 of the initial 3 patients enrolled at any dose level
experiences a DLT during the DLT assessment window, additional patients will be enrolled at
that dose level for a minimum of 6 evaluable patients for DLT. If a DLT is observed in 1 of
the 6 valuable patients at this dose level, dose escalation will proceed to the next
pre-defined dose level. If DLTs are observed in 2 or more of the 6 evaluable patients at a
given dose level, the dose escalation will be halted. If the dose escalation is completed due
to 2 or more DLTs at a dose level and that dose level is ≥50% higher than the previous dose
level, then an intermediate dose level may be evaluated for toxicity in the same manner as
described above. If the dose level is <50% higher than the previous dose level, in which only
3 DLT evaluable patients were enrolled, 3 additional patients will be enrolled at that dose
level to comprise 6 DLT evaluable patients.

The proposed dose escalation scheme comprises Cohorts 1 to 5 with dosing levels of 100 mg QD,
200 mg QD, 400 mg QD, 600 mg QD and 800 mg QD, respectively. The need for dose escalation
beyond 800 mg QD, the specific dose to be tested and the potential for twice-daily (BID)
dosing will be evaluated jointly by investigators and the sponsor based on the cumulative
clinical safety, pharmacokinetic, and preliminary efficacy data. Safety monitoring and
evaluation of dose escalation will be carried out by the Safety Review Committee, which will
be comprised of the sponsor's study team members (including medical monitor, safety monitor
and Pharmacokinetic scientist) and the site principal investigators. The adverse event
profile and serum concentration of HMPL-523 data will be evaluated to determine whether it is
safe to continue the assigned HMPL-523 dose for dose escalation or whether the dose should be
de-escalated to the lower dose level.

Dose Expansion Stage (Stage 2)

The adverse event profile, serum concentration, and preliminary anti-tumor activity of
HMPL-523 at the maximum tolerated dose(MTD)/recommended phase 2 dose(RP2D) will be further
evaluated in approximately 50 patients with relapsed or refractory indolent B-cell
non-Hodgkin's lymphomas. The tumor types of the dose expansion stage are restricted to:

- 10 patients with chronic lymphocytic leukemia/small lymphocytic lymphoma

- 10 patients with mantle cell lymphoma

- 10 patients with follicular lymphoma (Grade 1-3a)

- 10 patients with marginal zone lymphoma

- 10 patients with Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma.

Patients will receive HMPL-523 at the MTD/RP2D for continuous 28-day treatment cycles until
disease progression, death, intolerable toxicity, at investigator's discretion that the
patient can no longer benefit from the study treatment, patient withdrawal from the study, or
the end of study, whichever comes first.

Inclusion Criteria:

1. Signed informed consent form

2. Age ≥18 years

3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

4. Histologically confirmed lymphoma, including Hodgkin's lymphoma and non-Hodgkin's
lymphoma a. In the dose expansion stage, the tumor types are restricted to relapsed or
refractory chronic lymphocytic leukemia/small lymphocytic lymphoma, mantel cell
lymphoma, follicular lymphoma (Grade 1-3a), marginal zone lymphoma, and Waldenstrom's
macroglobulinemia/lymphoplasmacytic lymphoma.

5. Patients with relapsed or refractory lymphoma who have exhausted approved therapy
options

6. In the dose expansion stage, patients must have measurable disease for objective
response assessment, except for patients with chronic lymphocytic leukemia and
Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma.

7. Expected survival of more than 24 weeks as determined by the investigator

8. Male or female patients of child-bearing potential must agree to use double barrier
contraception, condoms, sponge, foams, jellies, diaphragm or intrauterine device,
contraceptives (oral or parenteral), Implanon®, injectables, or other measures to
avoid pregnancy during the study and for 90 days after the last day of treatment.
Post-menopausal females (>50 years old and without menses for >1 year) and women who
are surgically postmenopausal are exempt from this criterion.

Exclusion Criteria:

1. Patients with primary central nervous system lymphoma

2. Any of the following laboratory abnormalities: Absolute neutrophil count <1.5×109/L,
Hemoglobin <80 g/L, Platelets <75 ×109/L

3. Inadequate organ function, defined by the following: Total bilirubin >1.5 times the
upper limit of normal (× ULN), aspartate aminotransferase and/or alanine
aminotransferase >2.5 × ULN, Estimated Creatinine Clearance (CrCl) per Cockcroft-Gault
[Dose Escalation portion of trial (Stage 1) CrCl < 50 mL/min, Dose Expansion portion
of trial (Stage 2) CrCl < 30 mL/min], Serum amylase or lipase >ULN, International
normalized ratio >1.5 × ULN, or activated partial thromboplastin time >1.5 × ULN

4. Patients with clinically detectable second primary malignant tumors at enrollment, or
other malignant tumors within the last 2 years (with the exception of radically
treated basal cell or squamous cell carcinoma of the skin, in situ cervix, or in situ
breast cancer)

5. Any anti-cancer therapy, including chemotherapy, hormonal therapy, biologic therapy,
or radiotherapy within 3 weeks prior to initiation of study treatment

6. Herbal therapy within 1 week prior to initiation of study treatment

7. Prior use of any anti-cancer vaccine

8. Prior treatment with any spleen tyrosine kinase (SYK) inhibitors (eg, fostamatinib)

9. Prior administration of radioimmunotherapy within 3 months before initiation of study
treatment

10. Use of strong cytochrome P450 isoform 3A inhibitors and inducers and drugs metabolized
by cytochrome P450 isoform 3A, cytochrome P450 isoform 2B6, and cytochrome P450
isoform 1A2, and are identified as narrow therapeutic drugs within 7 days or 3
half-lives, whichever is longer, prior to initiation of study treatment

11. Adverse events from prior anti-cancer therapy that have not resolved to Grade ≤ 1,
except for alopecia

12. Prior autologous stem cell transplant within 6 months prior to initiation of study
treatment

13. Prior allogeneic stem cell transplant within 6 months prior to initiation of study
treatment or with any evidence of active graft versus host disease or requirement for
immunosuppressants within 28 days prior to initiation of study treatment

14. Clinically significant active infection (eg, pneumonia)

15. Major surgical procedure within 4 weeks prior to initiation of study treatment

16. Clinically significant history of liver disease, including cirrhosis, current alcohol
abuse, or current known active infection with human immunodeficiency virus, hepatitis
B virus, or hepatitis C virus.

17. Pregnant (positive serum beta human chorionic gonadotropin test) or lactating women

18. New York Heart Association Class II or greater congestive heart failure

19. Congenital long QT syndrome or correct QT interval using Fridericia's formula (QTcF)
>480 msec

20. Currently use medication known to cause QT prolongation or Torsades de Pointes

21. History of myocardial infarction or unstable angina within 6 months prior to
initiation of study treatment

22. History of stroke or transient ischemic attack within 6 months prior to initiation of
study treatment

23. Inability to take oral medication, prior surgical procedures affecting absorption, or
active peptic ulcer disease

24. Treatment in a clinical study within 30 days prior to initiation of study treatment

25. Any other diseases, metabolic dysfunction, physical examination finding, or clinical
laboratory finding that, in the investigator's opinion, gives reasonable suspicion of
a disease or condition that contraindicates the use of an investigational drug or that
may affect the interpretation of the results or renders the patient at high risk from
treatment complications.